Method and apparatus for an emergency lowering kit

ABSTRACT

A method and apparatus are disclosed for lowering a load on a direct current hoist motor during an electrical power interruption, the method including but not limited to determining in a crane processor that the electrical power interruption has occurred; and providing a brake assist current to shunt field on the direct current hoist motor to produce a counter torque in the hoist motor.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. Provisional PatentApplication Ser. No. 61/858,689 filed on Jul. 26, 2013 and entitled aSystem and Method for a Modular Retrofit Crane and 61/859,867 filed onJul. 30, 2013 and entitled A Method and Apparatus for a Modular Jack UpRig Assembly, which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION

Older pedestal cranes on offshore jack up oil rigs become inoperableover time and need to be replaced. The replacement process can be timeconsuming and expensive caused excessive oil rig down time.

SUMMARY OF THE INVENTION

A method and apparatus are disclosed for lowering a load on a directcurrent hoist motor during an electrical power interruption, the methodincluding but not limited to determining in a crane processor that theelectrical power interruption has occurred; and providing a brake assistcurrent to shunt field on the direct current hoist motor to produce acounter torque in the hoist motor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a prior art pedestal crane;

FIG. 2 depicts an illustrative embodiment of the present invention,showing a pedestal crane after a retrofit in a particular embodiment ofthe invention;

FIG. 3 depicts a particular embodiment of a braking resistor in anillustrative embodiment of the present invention;

FIG. 4 depicts a particular embodiment of an automated drill downschematic in an illustrative embodiment of the present invention;

FIG. 5 depicts a particular embodiment of an automated drill down videoinstruction in an illustrative embodiment of the present invention; and

FIG. 6 depicts a particular embodiment of an automated drill downinstruction manual using image recognition an illustrative embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

In a particular embodiment of the present invention replaces aLeTourneau pedestal crane with a retro fit crane kit provided by thepresent invention. The La Tourneau pedestal crane provides a motorgenerator set with open wiring. Replacement of the Le Tourneau pedestalcrane with similar technology is time consuming and inefficient.Prolonged time spent in replacement can result in extended and expensivedown time for an off shore jack up oil rig on which it is located. In aparticular embodiment the present invention enables rapid upgrading of aLeTourneau pedestal crane without excessive rig down time when performedduring a brief rig outage for an event such as a one week jack up rigrelocation.

In a particular embodiment, the present invention can include but is notlimited to functional modules to upgrade the existing pedestal crane.Providing the functional modules employing digital control, the presentinvention provides an upgrade package as a versatile way to upgradeolder existing pedestal crane equipment and improve safety, operation,and serviceability for the existing pedestal crane. Many of the olderexisting pedestal cranes such as the LeTourneau pedestal crane use motorgenerators to control the pedestal crane.

In a particular embodiment of the present invention, digital controlcomponents enable the functions of the system to be tuned or modified torespond as desired. An illustrative embodiment of the invention providesan ability to expand existing input output interfaces provided byretrofit crane package in an illustrative embodiment to includeadditional sensors, add additional alarms, or be configured to meet anend user's specific requirements.

In a particular illustrative embodiment, the present invention providesa system and method to enable installation, supervision andcommissioning of in retrofit pedestal crane upgrade package. In anillustrative embodiment a hook load instrumentation panel is providedalong with a high speed starter for boom motor, additional optionsincluding a crane spare parts kit, split cabin consoles, an auxiliaryhook control, a dual console configuration and a laptop computer withsoftware & communication hardware.

In a particular illustrative embodiment, safety is built into the systemand method by providing an easily connected enclosed equipment andwiring harness which creates a safer machinery space by eliminating openwiring which exposes rig maintenance personnel to electrical shock risk.In the past, serviceability has been a problem when it comes to themachinery space of a pedestal crane. With exposed electrical cables andcomponents throughout the entirety of the interior space of the pedestalcrane, thus requiring that electrical power to be removed for safeaccess into the interior area of the pedestal crane being replaced. Thisremoval of power creates problems for crane maintenance personnel tryingto troubleshoot an electrical problem.

In another illustrative embodiment of the present invention, allelectrical components are housed in stainless steel enclosures toprevent accidental electrical shock from exposed wiring. In a particularillustrative embodiment, a programmable logic controller (PLC) mastercontrol panel communicates with the control console and siliconcontrolled rectifier (SCR) drives, as well as monitor the cranes varioussensors and switches. It also monitors the health of the system andgives maintenance personnel a central diagnostic interface.

In an illustrative embodiment, at least one control console is providedwhich is provided with a Remote input and output (I/O) rack in thecontrol console(s), the operator control, indication, and alarming iscontrolled from the PLC caster control panel. Hoist and slew converterpanels are also provided. In a particular illustrative embodiment hoistmotors and slew motors are provided and powered by a plurality ofSiemens 6RA70 DC master drives, some of the latest developments indigital DC drive technology. These DC drives provide regenerativebraking, and are programmed with torque proving and “fail safe” brakecontrol logic for added safety. Hoist, boom and slew motorjunction-boxes are provided for a local connection point for the motorleads, gone is the hassle of dealing with a ball of rubber andelectrical tape.

In the event of a power interruption, safety is the number one concern.The hoist resistor grid also referred to herein as a “braking resistor”is provided for safety. The circulating currents from the motor will beredirected to the hoist resistor grid, which will aid the electric brakein bringing a hanging load. A replacement boom AC starter is providedfor single or two speed operation. In an illustrative embodiment, theincoming power feeds for the equipment are inside of closed equipmentenclosure such as a surge suppression panel to enhance safety. The surgesuppression panel does much more than that. It also absorbs the voltagespikes, which can damage the equipment and possibly cause an unsafecondition.

An illustrative embodiment of the system and method of the presentinvention provides a substantially complete system solution enablingreal added value in upgrading a pedestal crane. The package is designedto use many of the existing pedestal crane cables, distribution, andlighting panels, thus reducing cost of the installation.

A step by step computer generated instruction manual includes guidelinesfor identifying the cables and components that stay and the ones that goduring the remove and install retrofitting process. This work on thefront end speeds up the entire process. The computer generatedretrofitting instructions comprising audio, video and text in a nativelanguage selectable by the view takes an operator through the entireprocedure of retrofitting and commissioning an existing pedestal crane.The computer generated instructions, discussed below in conjunction withFIGS. 4, 5 and 6 assist an operator in with identifying equipment andsteps in the retrofitting process and what to do with it from start tofinish. Since the method and apparatus of the present invention systemare programmed and tested at the factory, the computer generatedinstruction manual also demonstrates you how to commission pedestalcrane after the retrofitting is complete.

In the past crane kit retrofit installations have been complexoperations requiring the interconnections of hundreds of parts used toreplace or retrofit an existing pedestal crane on a jack up rig. Thepresent invention preassembles components into modular sections into acrane retrofit kit so that there is an order of magnitude lesscomplexity to assemble the crane retrofit kit once the crane retrofitkit arrives at a foreign destination. The modular retrofit kit comprisessealed enclosed equipment enclosure modules which are tested and sealedand then certified during manufacture. The certified modules are thenshipped to a foreign destination where the sealed modules are connectedtogether for a simplified assembly. The simplified modular approachhelps to overcome the limitations of language barriers and availabledocumentation during assembly at a foreign destination on a jack up rigor a ship.

An emergency lowering kit is provided as an alternative method andapparatus for lowering a crane's suspended load in the event that themain power to the crane is interrupted. By utilizing stored energy in abattery bank, the crane hoist brake coils can be energized to allow fora safe and controlled decent of the load. The brake contactor in anemergency lowering control panel is electrically interlocked with a mainbrake contactor in the hoist converter panel to prevent inadvertentconnection of the main AC power to the DC battery bank.

Turning now to FIG. 1, FIG. 1 depicts a schematic drawing of an existingpedestal crane that has aged and deteriorated and is in need of aretrofit. In an illustrative embodiment of the invention an EPDL120Crane Kit is provided as an upgrade package designed to retrofit thecontrols of a LeTourneau PCM-120 pedestal crane 100. The existingcontrols of a LeTourneau PCM-120 crane consist of DC motor-generatorsets 101, 103 and 105 with a power conversion scheme capable of poweringthe hoist motor 120 and slew motor 116 and boom motor 118. The hoistmotor 118 and slew motor 116 and boom motor 120 are located inside ofcrane housing 102.

Turning now to FIG. 2, FIG. 2 depicts an illustrative embodiment of thepresent invention, showing a particular embodiment of a pedestal craneafter a retrofit. As shown in FIG. 2, in a particular embodiment of thepresent invention, an EPDL120 crane kit is provided that replaces themotor-generator sets 101, 103 and 105 controllers of the existingpedestal crane. The motor-generator sets are replaced by digitallycontrolled SCR drives. SCR drive 150 is installed for the slew motor,SCR drive 152 is installed for the boom motor and SCR drive 154 isinstalled for the hoist motor. The SCR drives are 4 quadrant maintainingthe ability to power the motors in either direction and electricallybrake the motors. In particular illustrative embodiment, a system andmethod are provided to perform functions to substantially preventcommutation failure. The hoist converter and slew converter both measurethe AC line voltage. If the AC line voltage is too low, the SCR drivewill not regenerate power to the AC line. In a particular embodiment,reactors are installed across the hoist, boom and slew DC motors toimprove the performance of the hoist, boom and slew DC motors.

In a particular illustrative embodiment, a crane processor 114, anon-transitory computer readable medium 126 and display 128 are providedinside of the crane housing 102. A computer program comprisinginstructions stored in the non-transitory computer readable medium 126.In a particular embodiment, the hoist converter 154 is in datacommunication with the crane processor 114. In one particular embodimentof the invention, data communication performed over a wireless wirelessfidelity (WIFI) network. In another embodiment data communicationperformed over a combination of a hard-wired and a wireless WIFInetwork. In one particular embodiment of the invention, the craneprocessor is data communication with the hoist SCR drive 154. In thepresent patent application, the phrase “data communication” is used tomean that data is exchanged between two devices that are in datacommunication over a wireless or hard wire communication link. When thehoist SCR drive is not able to be activated for any reason (such as thesupplied input AC line voltage being supplied to the hoist SCR drive istoo low), a spring loaded fail-safe brake switch 136 is provided thatcloses to engage a brake when power is not applied. The spring closesand engages a mechanical brake 134. The engaged mechanical brake on thehoist motor substantially stops rotation of the hoist motor tosubstantially discontinue up and down motion of a load 109 suspendedfrom the hoist hook 108. In particular illustrative embodiment, whenpower interruption occurs, a braking resistor 139 is automaticallyconnected across terminals of the hoist motor by the normally closedfail-safe brake switch. The braking resistor provides a dynamic brakingcounter torque in the hoist motor in the case of a power interruptionwhen the power interruption occurs when the crane is loaded, that isduring a lifting or lowering operation of a load 109 suspended fromhoist hook 108 and hoist line 107. In a particular embodiment of theinvention, a plurality of accelerometers are provided and installed. Afirst three axis digital accelerometer 113 is installed on the distalend, i.e., crane boom 106 tip and a second three axis accelerometer 117is installed on the hoist hook. In a particular embodiment, wirelessdata communication, comprising data exchanged between the processor andother electronic equipment inside and outside of the crane housing,occurs between the crane processor and accelerometers 113 and 117.

The first accelerometer is provided and installed for monitoring, thedisplacement, velocity and acceleration of the distal end of the craneboom 106. The second accelerometer is provided and installed formonitoring and the displacement, velocity and acceleration of the hoisthook. In another particular embodiment, wind speed is measured by ananemometer 141 mounted on top of the crane housing 102. In anotherparticular embodiment, wave height and direction is measured by a wavemeasuring buoy (not shown) that is deployed near the pedestal cranelocation. Wireless data transmission elements 115, 121, 131 and 144 areinstalled to provide data communication between the crane processor, theoperator console, the accelerometers and the anemometer.

The crane processor computer program embedded in the non-transitorycomputer readable medium provides overall data acquisition, logging anddisplay. Data is sent by sensory elements, including but not limited tothe accelerometers, switch closures, anemometer readings (wind speed anddirection), SCR drive state data (on, off), brake assist data (on, off,current level, brake assist resistor value), braking resistor data (on,off, current level, brake assist resistor value) and operator inputs tothe crane processor. The data is displayed on the crane processordisplay 128 screen inside the crane housing 102. The crane processormonitors accelerometer 113 to determine crane boom velocity andacceleration. Hoist hook velocity and acceleration are monitored by thecrane processor computer program. In a particular illustrativeembodiment, the crane processor computer program performs peremptorycorrective action when one or more monitored values from the sensoryelements reaches a predefined maximum or minimum allowed value.Monitored values are presented by the crane processor to a craneoperator in real-time. Monitored data are sent over a wireless link tothe crane processor and an operator processor 132 on a crane operatordisplay 133 on a crane operator console 135 in a crane operator cabin130. In another particular embodiment, wind speed and direction aremeasured by an anemometer 141 installed on the crane housing. Themeasured wind speed and direction are sent to the crane processor overthe wireless link. Rechargeable batteries attached to photovoltaic cells114, 144 and 121 are provided to recharge and power the accelerometersand anemometer. The batteries provide electrical power to theanemometer, accelerometers and wireless communicationtransmitters/receivers installed on the crane boom tip and the hoisthook.

Accelerometer 113 is mounted on the boom tip to provide boom tipvelocity oriented outputs acceleration data to the processor indicatesboom tip velocity and boom tip acceleration. When either the boom tipvelocity or acceleration exceeds a predetermined value the craneprocessor intercedes by sending a command to implement peremptorycorrective action by slowing down or braking the boom motor.Accelerometer 117 is mounted on the hoist hook to provide hoist hookvelocity and acceleration data to the processor indicates boom tipvelocity and acceleration. Hoist hook acceleration is an indication ofload lowering velocity and acceleration. Thus, if the hoist hookacceleration exceeds a predetermined value the crane processorintercedes by sending a command to implement peremptory correctiveaction by slowing down or braking the boom motor.

FIG. 3 depicts an illustrative embodiment of the present invention,showing a particular embodiment of a braking resistor. Turning now toFIG. 3, a more detailed schematic drawing of a particular illustrativeembodiment of the emergency lowering kit 300 is depicted in a schematic.In a particular embodiment of the invention, hoist motor leads 321 and323 are wired into a hoist motor junction box 341. The junction box 341comprises a switch enclosure for automatically connecting the brakingresistor 328 across the hoist motor leads 321 and 323. A similarjunction box is provided for the boom and slew motors. In anotherembodiment, the braking resistor and emergency lowering kit method andapparatus are provided for the slew motor. In another embodiment, thebraking resistor and emergency lowering kit method and apparatus isprovided for the boom motor. When electrical power to the crane hoistmotor is lost, the crane processor maintains power via a rechargeableback up battery 310. When power is lost the hoist brake 319 which isspring loaded to be normally closed or engaged when power is notapplied, engages to substantially stop rotation of the hoist motor andthe associated descent of the load attached to the hoist hook to preventan accident from the load free falling during a power interruption. In aparticular embodiment a brake release push button is provided to enablean operator to manually activate. A back up battery 310 is provided toenergize brake relay 318 via a wireless data link to release the hoistbrake 319 to allow the hanging load suspended from the hoist hook to belowered safely. In another particular embodiment, during a powerinterruption the processor senses a power interruption and provides acommand over a wireless connection to sends the command to energize theswitch 331 to place the braking resistor 328 across the terminals 325and 327 of the hoist motor. In a particular illustrative embodiment, thehoist motor is a compound DC motor having an armature and field windingwired in series and a shunt field. A switchable reversing rectifiercircuit is wired between the armature and field winding to enablereversal of the hoist motor direction of rotation.

During the power interruption, the crane processor uses provides back upbattery 310 to energize brake relay 318 via a wireless data link torelease the hoist brake 319 to allow the hanging load suspended from thehoist hook to be lowered safely. During a power interruption theprocessor uses a wireless connection to send a command to energize aswitch 331 to connect the braking resistor 328 across the terminals 325and 327 of the hoist motor inside of a sealed junction box. When thebrake is released during a power interruption, the weight of the load onhoist hook, which is connected to the hoist motor, causes the hoistmotor to “freewheel” or spin freely. This freewheeling during a powerinterruption turns the hoist motor into a generator. The freewheelinghoist motor generates voltage and thus current flow through the brakingresistor thereby dumping energy into the braking resistor producing acounter torque to resist the rotation of the freewheeling hoist motor.The faster the hoist motor spins during freewheeling, the more voltageand current hoist motor generates. The voltage generated by thefreewheeling hoist motor thus limits the rotation of the hoist motor andthe speed at which a load hanging on the hook attached to the hoistmotor descends for the hanging position.

The crane processor runs on backup power during a power interruption andstays in data communication with the variable resistance brakingresistor 328 and the emergency lowering kit 300 and variable resistancebrake assist resistor 333. The braking resistor 328 is disconnectedduring normal crane hoist motor operations. When the In a particularillustrative embodiment of the invention, an emergency lowering kit 300is provided to help safely lower a load hanging from hook 108 during apower outage when the power to the hoist motor is unexpectedlyinterrupted during a crane operation. The emergency lowering kit isschematically depicted and discussed below in conjunction with FIG. 3.If such a power interruption failure occurs, the crane processorautomatically closes switch 329 to engage the braking resistor 328. Thebraking is automatically switched in across the hoist motor terminals.The braking resistor 328 provides a path for current from the DC hoistmotor 120. The current produces motor counter torque that assists inbraking the hoist motor during a power loss to allow a more controlleddescent of a load left hanging from the hoist hook attached to the hoistmotor during a power interruption.

In another particular embodiment of the invention, during an unexpectedpower interruption, the crane processor provides a wireless command toenergize and close a brake assist switch 312 to provide an electricalcurrent from the back up battery 310 through rectifier 320 to a shuntfield 322 on the hoist motor 120. In another particular embodiment, thebrake assist resistor 333 is a programmable variable resistor is placedin series with the backup battery to control the amount of currentsupplied to the shunt field. The crane processor controls the value forthe variable resistance brake assist resistor 333. The brake assistswitch closure provides a path from the rechargeable back up battery 310to the hoist motor shunt field 322 and injects additional current intothe hoist motor by injecting current into the hoist motor shunt field togenerate additional hoist motor counter torque to further assist inbraking the hoist motor during a power interruption to gently lower aload on the hoist hook. In a particular embodiment, the crane hoistmotor is a compound motor having an armature field and a series fieldwired in series.

The crane hoist motor additionally has a shunt field. In a particularembodiment the shunt field uses 75 percent of the hoist motor current.When the hoist brake is released, the load on the hoist hook is allowedto freefall. During freefall the hoist motor freewheels (spins freely)due to weight of the load on the hoist hook. The freewheeling hoistmotor produces a current at terminals 321 and 323 that is dumped intothe braking resistor 328 when the braking resistor switch 329 is closed.A counter torque is produced by the freewheeling hoist motor. The boommotor is equipped with an emergency lowering kit also to allowcontrolled lowering of the boom during a power outage.

In a particular embodiment, safety features are provided by theprocessor. When the crane processor determines that the boom up relay isenergized and both of the first boom upper limit switch 124 and thesecond boom upper limit switch 122 are activated, an Emergency Stop isinitiated by the crane processor after 0.5 seconds. When the craneprocessor determines that the boom up contactor is energized without theboom up command issued, an Emergency Stop command is initiated by thecrane processor after 0.5 seconds. When the crane processor determinesthat boom down contactor is energized without the boom down commandissued, an Emergency Stop is initiated by the crane processor after 0.5seconds. When the processor determines that the slew drive is drivingleft and the both the first and second left limit switches areactivated, an Emergency Stop is initiated by the processor after 0.5seconds. When the crane processor determines that the slew drive isdriving right and both the first and second right limit switches areactivated, an Emergency Stop is initiated by the processor after 0.5seconds. When the hoist drive is driving up and the upper limit switchis activated, an Emergency Stop is initiated after 0.5 seconds. In aparticular illustrative embodiment, a Surge suppression module isprovided in the crane housing to protect against voltage spikes on thehoist, boom and slew motors and crane processor and other electronicsand electrical devices described herein (hereinafter the “craneelectronics”) and provided in a particular embodiment of the presentinvention. In a particular illustrative embodiment, the equipment andcrane electronics are protected in NEMA 4× enclosures.

The hoist resistor grid (also referred to as “braking resistor”) aidsthe hoist motor brake during a power failure. Ground fault monitoring ofthe 120V power is implanted. In a particular embodiment, the craneelectronics, communication devices and wireless communication devicesare provided with a separate uninterruptable power supply. In anotherparticular embodiment, the crane electronics are provide with their ownpower supply isolated from all I/O circuits. The hoist controls provideinternal torque proving and brake control logic to prevent loadslipping. In another particular embodiment, faulty upper, lower, leftand right limit switches can be quickly bypassed using keyed switches toallow operation of the crane. In another particular embodiment the firstlimit switch is provided with a contact arm that opens a normally closedlimit switch. In another particular embodiment of the invention thefirst limit switch is a pair of limit switches wired in parallel,wherein the pair of limit switches comprise one normally open limitswitch and on normally closed limit switch so that both the normallyopen limit switch and on normally closed limit switch must be activatedto indicate that the boom has activated of the first limit switch. Inanother particular embodiment, the second limit switch comprises aninductive proximity sensors that activates when the boom travels closeenough to the second limit switch to activate the inductive second limitswitch.

In another particular embodiment the braking resistor is a variableresistor that can be manipulated to provide more or less resistanceproportional to the speed or descent of the load and hook as reportedfrom the hook accelerometer. When the load is descending faster than apreprogrammed maximum hook velocity, the resistance of the variablebraking resistor on the hoist motor is increased to slow down thevelocity of the descending load attached to the hook. In anotherembodiment, when the load is descending slower than a preprogrammedminimum velocity, the resistance of the variable braking resistor isdecreased to increase the velocity of the descending. In anotherembodiment a neural network is provided in the crane processor tomonitor and learn maximum hook velocities at which prior operations haveswitched in the braking resistor, increased the resistance of thebraking resistor. In another embodiment a neural network is provided inthe crane processor to monitor and learn minimum hook velocities atwhich prior operations have switched in the braking resistor, decreasedthe resistance of the braking resistor. In a particular embodiment, theneural network automatically switches in the braking resistor to connectit across the terminals a hoist, slew or boom motor and sets theresistance of the braking resistor to the resistance value learned bythe neural network for a measured value for the velocity of the hook.

In another particular embodiment, the computer program in the craneprocessor tests the first and second upper limit switches. The computerprogram periodically activates the crane boom motor to move to aposition at which both first and second upper limit switches areactivated to insure the first and second upper limit switches are inworking order. The computer program will not allow crane boom operationwhen either of a first or second upper limit switches have not beentested or have been tested and a failure is indicated. In anotherparticular embodiment, the computer program in the crane processor teststhe first and second lower limit switches. The computer programperiodically activates the crane boom motor to move to a position atwhich both first and second lower limit switches are activated to insurethe first and second lower limit switches are in working order. Thecomputer program will not allow crane boom operation when either of afirst or second lower limit switches have not been tested or have beentested and a failure is indicated.

In another particular embodiment, the computer program in the craneprocessor tests the first and second right limit switches. The computerprogram periodically activates the crane slew motor to move to aposition at which both first and second right limit switches areactivated to insure the first and second right limit switches are inworking order. The computer program will not allow crane slew motoroperation when either of a first or second right limit switches have notbeen tested or have been tested and a failure is indicated. In anotherparticular embodiment, the computer program in the crane processor teststhe first and second right limit switches. The computer programperiodically activates the crane slew motor to move to a position atwhich both first and second right limit switches are activated to insurethe first and second right limit switches are in working order. Thecomputer program will not allow crane boom operation when either of afirst or second right limit switches have not been tested or have beentested and a failure is indicated.

In another particular embodiment, the computer program in the craneprocessor tests the first and second left limit switches. The computerprogram periodically activates the crane slew motor to move to aposition at which both first and second left limit switches areactivated to insure the first and second left limit switches are inworking order. The computer program will not allow crane slew motoroperation when either of a first or second left limit switches have notbeen tested or have been tested and a failure is indicated. In anotherparticular embodiment, the computer program in the crane processor teststhe first and second left limit switches. The computer programperiodically activates the crane slew motor to move to a position atwhich both first and second left limit switches are activated to insurethe first and second left limit switches are in working order. Thecomputer program will not allow crane boom operation when either of afirst or second left limit switches have not been tested or have beentested and a failure is indicated.

In another particular embodiment the brake assist current is varied byadjusting the resistance of a programmable variable brake assistresistor that is manipulated to provide more or less resistance. Thebrake assist resistance is adjusted by the crane processor to beproportional to the speed or descent of the hook as reported from thehoist hook accelerometer. When the load on the hoist hook is descendingfaster than a preprogrammed maximum hook velocity, the resistance of thevariable brake assist resistor on the hoist motor is decreased to slowdown the velocity of the descending load attached to the hook. Inanother embodiment, when the load is descending slower than apreprogrammed minimum velocity, the resistance of the variable brakeassist resistor is decreased to increase the velocity of the descendingload. In another embodiment a neural network is provided in the craneprocessor to monitor and learn maximum hook velocities at which prioroperations have switched in the brake assist and decreased theresistance of the brake assist resistor. In another embodiment a neuralnetwork is provided as software embedded in the computer readable mediumin the crane processor. The neural network monitors the inputs fromsensory elements to store and process the inputs to learn minimum hookvelocities at which prior operations have switched in the brake assistresistor and increased the resistance of the braking resistor. In aparticular embodiment, the neural network automatically switches in thebrake assist to add current to a shunt field of a hoist, slew or boommotor and sets the resistance of the brake assist resistor to theresistance value learned by the neural network for a measured value forthe velocity of the descending hook.

In another particular embodiment, the crane processor further comprisesa programmable logic controller (PLC). In another particular embodiment,a PLC master control panel communicates with the Control Console and theSCR Drives. It also receives and monitors sensors and safety limitswitches. In another particular embodiment the PLC master control panelis enclosed in a sealed equipment enclosure that is cooled with anevaporative alcohol. The emergency lowering kit is also provided in asealed equipment enclosure that is cooled with an evaporative alcoholcooling apparatus.

In another embodiment, a hoist converter panel is provided that powersthe hoist motor. The hoist converter panel includes but is not limitedto an SCR drive and drive controls and is also provided in a sealedequipment enclosure that is cooled with an evaporative alcohol chillingapparatus. In another particular embodiment, an auxiliary hoistconverter panel is provided that powers a second auxiliary hoist DCmotor. It contains and SCR drive and drive controls. In anotherparticular embodiment a prefabricated wiring harness is provided toconnect the sealed equipment enclosures to existing equipment in thecrane housing during the remove and install retrofit process.

In another embodiment, a slew converter panel is provided that powersthe slew motor. The slew converter panel contains and SCR drive anddrive controls and is also provided in a sealed equipment enclosure thatis cooled with an evaporative alcohol. In a particular embodiment,digital controls are provided in method and apparatus for a PedestalCrane upgrade package which provides a versatile way to upgrade theequipment and improve the safety, operation, and serviceability of aPedestal Crane. Digital control components allow the functions of thesystem to be tuned or modified. In an illustrative embodiment of theinvention, the crane processor further provides for automatic assistingduring Installation, Supervision and Commissioning of the retrofittingof a pedestal crane.

Serviceability has sometimes been a problem when it comes to themachinery space of a pedestal crane. With exposed cables and componentsthroughout, the power has to be removed for safe access into the area.This creates problems for maintenance personnel trying to troubleshootan electrical problem. In a particular embodiment of the invention anupgrade package comprising a remove and install retrofitting system andare provided in which the components are housed in stainless steelenclosures to prevent accidental shock.

Turning now to FIG. 4, in a particular illustrative embodiment 400, thesystem and method of the present invention is designed to retain asubstantial portion of the existing cables, distribution, and lightingpanels, thus reducing cost of the installation. An online installationmanual 420 is presented on the auxiliary computer display that guidesinstallation personnel during the pedestal crane retrofit process. Asshown in FIG. 4, in an illustrative embodiment, an automatedretrofitting install and remove instruction manual 402 is provided thatprovides operator guidelines for identifying the cables and componentsthat are retained and the components that are removed. This work on thefront end speeds up the entire process. The automated installationmanual is a computer program that is stored in a non-transitory computerreadable medium of the crane processor and auxiliary crane processor. Ina particular embodiment, the automated installation manual computerprogram is stored on the crane processor and displayed on a display andinput device such a computer keyboard connected to the crane processor.In another particular embodiment, the automated installation manualcomputer program is stored on a non-transitory computer readable mediumon an auxiliary installation processor and displayed on a display andinput device. The input device is a computer keyboard connected to theauxiliary installation processor. In a particular embodiment theauxiliary installation processor is a tablet computer. In anotherembodiment the auxiliary installation processor is a smart phone.

As shown in FIG. 4, a block diagram 402 of components 410, 412, 414,411, 413 and 415 of an equipment retrofitting procedure for an existingcrane is shown on the auxiliary computer display. Installation personnelselect a component 415 from the equipment retrofitting procedure whichis expanded to depict a schematic component display 403 by the auxiliaryinstallation processor and presented on the auxiliary installationprocessor display. A component 420 is selected from the schematicdisplay and a bill of materials and installation instructions 406 arepresented on the auxiliary computer describing the component isdisplayed. The bill of materials comprises a description of thecomponents, the components inputs and outputs, equivalents andsuppliers. In the present specification, the term “presented” is used tomeans rendered in a humanly perceptible fashion such as a visualpresentation including but not limited text display, video display andaural audio output that can be perceived the installation personalperforming the retrofit, remove and install on the pedestal crane.

Turning now to FIG. 5, in another embodiment 500, installationinstructions are provided on a step by step basis. The retrofitprocedure, comprising a series of removal and installation procedurestep icons 502, 504, 506, 508, 510 and 512 are presented on a displayfor the auxiliary crane processor. An operator selects a step icon 506in the process and a video 520 is displayed on the display for theauxiliary crane processor. The video explains how to perform theselected retrofit step in the removal and installation process. Theoperator can select an object 522 in the video 520 to enter a textualdisplay 530 of the process step specifically related to the video objectdescribing the retrofit remove and install instructions for theequipment identified in the video object.

Turning now to FIG. 6, in another embodiment, an operator 610 enters adoor 612 into crane housing 102 and uses a camera 616 to take a pictureof an equipment 614 installed inside of the crane housing 102. Thepicture is transmitted over a wireless 620 connection to the craneauxiliary processor 622. A computer program embedded in the auxiliarycrane processor computer readable medium performs image recognition toidentify the equipment in the picture and presents a series of steps 624in the retrofit procedure explaining how to remove and replace theidentified equipment, comprising a series of removal and installationregarding the specific retrofit procedure for the equipment identifiedin the picture. In another embodiment the picture is transmitted over awireless connection to a cloud computer such as commercially availablecloud storage over the internet where the picture is processed by acloud computer. A computer program embedded in a cloud computer readablemedium performs image recognition to identify the equipment in thepicture and displays a series of steps in the retrofit procedure,comprising a series of removal and installation regarding the specificretrofit procedure for the equipment in the picture, comprising a seriesof removal and installation for the equipment in the picture.

The retrofit procedure is displayed on the auxiliary crane computerdisplay, comprising a series of removal and installation takes theoperator through the entire procedure of retrofitting your crane. Fromidentifying the equipment the operator is currently working with, wherethe operator is in the retrofit process, how to remove and install theequipment in step by step video including audio or textual display in aselectable native language of the operator from start to finish. Theinstallation process instructions are programmed and tested at thefactory. The installation instruction provide information to theoperator on how to commission the crane after the retrofit has beencompleted.

The foregoing examples of illustrative embodiments are for purposes ofexample only and is not intended to limit the scope of the invention.Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present invention, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present invention contemplates a non-transitory machine readablestorage medium containing instructions, so that a device connected to anetwork environment can send or receive voice, video or data, and tocommunicate over the network using the instructions. The instructionsmay further be transmitted or received over a network via the networkinterface device. The non-transitory machine readable storage medium mayalso contain a data structure for containing data useful in providing afunctional relationship between the data and a machine or computer in anillustrative embodiment of the disclosed system and method.

While the non-transitory computer-readable storage medium is shown in anexample embodiment to be a single medium, the term “computer-readablemedium” should be taken to include a single medium or multiple media(e.g., a centralized or distributed database, and/or associated cachesand servers) that store the one or more sets of instructions. The term“computer-readable medium” shall also be taken to include any mediumthat is capable of storing, encoding or carrying a set of instructionsfor execution by the machine and that cause the machine to perform anyone or more of the methodologies of the present invention. The term“computer-readable medium” shall accordingly be taken to include, butnot be limited to: solid-state memories such as a memory card or otherpackage that houses one or more read-only (non-volatile) memories,random access memories, or other re-writable (volatile) memories;magneto-optical or optical medium such as a disk or tape; and carrierwave signals such as a signal embodying computer instructions in atransmission medium; and/or a digital file attachment to e-mail or otherself-contained information archive or set of archives is considered adistribution medium equivalent to a tangible storage medium.Accordingly, the invention is considered to include any one or more of acomputer-readable medium or a distribution medium, as listed herein andincluding art-recognized equivalents and successor media, in which thesoftware implementations herein are stored.

Although the present specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the invention is not limited to such standards andprotocols. Each of the standards for Internet and other packet switchednetwork transmission (e.g., TCP/IP, UDP/IP, HTML, and HTTP) representexamples of the state of the art. Such standards are periodicallysuperseded by faster or more efficient equivalents having essentiallythe same functions. Accordingly, replacement standards and protocolshaving the same functions are considered equivalents.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived there from, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. The figures are also merelyrepresentational and may not be drawn to scale. Certain proportionsthereof may be exaggerated, while others may be minimized. Accordingly,the specification and drawings are to be regarded in an illustrativerather than a restrictive sense.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separately claimed subject matter.

The invention claimed is:
 1. A method for lowering a load on a directcurrent hoist motor during an electrical power interruption to thedirect current hoist motor, the method comprising: determining in acrane processor that an electrical power interruption to the directcurrent hoist motor has occurred; and providing a brake assist currentto a shunt field on the direct current hoist motor to produce a countertorque in the direct current hoist motor; electrically connecting avariable resistance brake assist resistor in series with a dc powersupply and the shunt field wherein a brake assist resistance value forthe variable resistance brake assist resistor is controlled by the craneprocessor; and varying the brake assist resistance value proportionatelyto a measured hoist hook speed to proportionately increase the brakeassist value to proportionately provide counter torque with an increasein hoist hook speed.
 2. The method of claim 1, the method furthercomprising: electrically connecting a brake assist resistor in serieswith a dc power supply and the shunt field.
 3. The method of claim 2,wherein an accelerometer measures hoist hook speed.
 4. The method ofclaim 3, the method further comprising: placing a braking resistoracross a pair of electrical terminals on the hoist motor to create acounter torque in the hoist motor wherein the counter torque opposes atorque of a freewheeling hoist motor with an attached load.
 5. Themethod of claim 4, sensing a first normally open switch limit switch anda second normally closed limit switch.
 6. A system for lowering a loadon a direct current hoist motor during an electrical power interruption,the system comprising: a crane auxiliary processor in data communicationwith a non-transitory computer readable medium; a computer programembedded in the non-transitory computer readable medium, the computerprogram comprising instructions that when executed by a computer,perform functions, the computer program further comprising: instructionsto determine that the electrical power interruption has occurred;instructions to electrically connect a brake assist resistor in serieswith a dc power supply and the shunt field; and instructions to providea brake assist current to shunt field on the direct current hoist motorto produce a counter torque in the hoist motor wherein the brake assistresistor is a variable resistance resistor wherein a brake assistresistance value is controlled by the crane processor, the methodfurther comprising: instructions to vary the brake assist resistancevalue proportionately with a measure hoist hook speed to proportionatelyincrease the counter torque with an increase in hoist hook speed.
 7. Thesystem of claim 6, the computer program further comprising: instructionsto electrically connect a brake assist resistor in series with a dcpower supply and the shunt field.
 8. The system of claim 7, wherein thebrake assist resistor is a variable resistance resistor wherein a brakeassist resistance value is controlled by the crane processor, the methodfurther comprising: instructions to vary the brake assist resistancevalue proportionately with a measure hoist hook speed to proportionatelyincrease the counter torque with an increase in hoist hook speed.
 9. Thesystem of claim 8, the computer further comprising: instructions to senda command to a braking resistor relay to electrically a braking resistoracross the terminal of the hoist motor to create a counter torque in thehoist motor wherein the counter torque opposes the torque of afreewheeling hoist motor with an attached load.
 10. The system of claim9, wherein the braking resistor is a variable resistance resistorwherein a braking resistor resistance value is controlled by the craneprocessor, the computer program further comprising: instructions to varythe braking resistor resistance value proportionately with a measurehoist hook speed to proportionately increase the counter torque with anincrease in hoist hook speed.